New measurement of the K-+/- -> pi(+/-)mu(+)mu(-) decay

Batley, J. R.; Kalmus, G.; Lazzeroni, C.; Munday, D. J.; Slater, M. W.; Wotton, S. A.; Arcidiacono, R.; Bocquet, G.; Cabibbo, N.; Ceccucci, A.; Cundy, D.; Falaleev, V.; Fidecaro, M.; Gatignon, L.; Gonidec, A.; Kubischta, W.; Norton, A.; Maier, A.; Patel, M.; Peters, A.; Balev, S.; Frabetti, P. L.; Goudzovski, E.; Hristov, P.; Kekelidze, V.; Kozhuharov, V.; Litov, L.; Madigozhin, D.; Marinova, E.; Molokanova, N.; Polenkevich, I.; Potrebenikov, Y.; Stoynev, S.; Zinchenko, A.; Monnier, E.; Swallow, E.; Winston, R.; Rubin, P.; Walker, A.; Baldini, W.; Ramusino, A. C.; Dalpiaz, P.; Damiani, C.; Fiorini, M.; Gianoli, A.; Martini, M.; Petrucci, F.; Savrie, M.; Scarpa, M.; Wahl, H.; Bizzeti, A.; Lenti, M.; Veltri, M.; Calvetti, M.; Celeghini, E.; Iacopini, E.; Ruggiero, G.; Behler, M.; Eppard, K.; Kleinknecht, K.; Marouelli, P.; Masetti, L.; Moosbrugger, U.; Morales, C. M.; Renk, B.; Wache, M.; Wanke, R.; Winhart, A.; Coward, D.; Dabrowski, A.; Martin, T. F.; Shieh, M.; Szleper, M.; Velasco, M.; Wood, M. D.; Cenci, P.; Pepe, M.; Petrucci, M. C.; Anzivino, G.; Imbergamo, E.; Nappi, A.; Piccini, M.; Raggi, M.; Valdata Nappi, M.; Cerri, C.; Fantechi, R.; Collazuol, Gianmaria; Dilelia, L.; Lamanna, G.; Mannelli, I.; Michetti, A.; Costantini, F.; Doble, N.; Fiorini, L.; Giudici, S.; Pierazzini, G.; Sozzi, M.; Venditti, S.; Bloch Devaux, B.; Cheshkov, C.; Cheze, J. B.; Beer, M. D.; Derre, J.; Marel, G.; Mazzucato, E.; Peyaud, B.; Vallage, B.; Holder, M.; Ziolkowski, M.; Biino, C.; Cartiglia, N.; Marchetto, F.; Bifani, S.; Clemencic, M.; Lopez, S. G.; Dibon, H.; Jeitler, M.; Markytan, M.; Mikulec, I.; Neuhofer, G.; Widhalm, L.

doi:10.1016/j.physletb.2011.01.042

A sample of 3120 K-+/- -> pi(+/-)mu(+)mu(-) decay candidates with (3.3 +/- 0.7)% background contamination has been collected by the NA48/2 experiment at the CERN SPS, allowing a detailed study of the decay properties. The branching ratio was measured to be BR = (9.62 +/- 0.25) x 10(-8). The form factor W(z), where z = (M-mu mu/M-K)(2), was parameterized according to several models. In particular, the slope of the linear form factor W(z) = W-0(1 + delta z) was measured to be delta = 3.11 +/- 0.57. Upper limits of 2.9 x 10(-2) and 2.3 x 10(-2) on possible charge asymmetry and forward-backward asymmetry were established at 90% CL. An upper limit BR(K-+/- -> pi(-/+)mu(+/-)mu(+/-)) < 1.1 x 10(-9) was established at 90% CL for the rate of the lepton number violating decay. (C) 2011 Elsevier B.V. All rights reserved.